Coordinate ↔ What3Words & Plus Code Converter
Convert any latitude/longitude to a What3Words address and Google Plus Code instantly. Decode Plus Codes back to coordinates. Built for delivery logistics, emergency services, and navigation.
Converting...
Enter coordinates or a Plus Code above, then click Convert to get the What3Words address and Plus Code.
Location Code Precision — Nested View
What Is What3Words and How Does It Work?
What3Words is a proprietary geocoding system that divides the entire surface of the Earth into 57 billion 3 m × 3 m squares, each assigned a unique combination of three common words. The address filled.count.soap always refers to exactly one spot on the planet, nowhere else.
The system was designed to solve the "last mile" delivery problem: most of the world's roads do not have official addresses. A three-word address can be communicated verbally, typed without error, and looked up instantly — advantages that raw decimal coordinates cannot offer to non-technical users.
What Is a Google Plus Code (Open Location Code)?
A Plus Code is an open-source location code developed by Google, also called Open Location Code (OLC). A full 10-digit code like 87G8Q2PF+GF encodes a ~14 × 14 m area. The encoding algorithm is fully public (Apache 2.0 licence) and runs entirely offline — no API key, no internet connection, no rate limits.
Plus Codes appear in Google Maps when you long-press any location. They are also used in humanitarian mapping (OpenStreetMap, Missing Maps) and disaster response logistics where connectivity is unreliable.
What3Words vs Plus Code: Key Differences
| Feature | What3Words | Plus Code (OLC) |
|---|---|---|
| Cell size | ~3 × 3 m | ~14 × 14 m (10-digit) |
| Algorithm | Proprietary | Open source, Apache 2.0 |
| Works offline | No — API required | Yes — pure algorithm |
| Human readability | Excellent (spoken words) | Good (alphanumeric) |
| Free tier | Yes (1,000 req/day) | Unlimited (no key needed) |
| Primary users | Emergency services, delivery | Google Maps, humanitarian aid |
| Example | filled.count.soap | 87G8Q2PF+GF |
Use Cases: Who Needs Location Codes?
Emergency Services
UK ambulance and police services use What3Words to dispatch to exact doorstep locations. In rural areas with no street addresses, callers read three words instead of map coordinates.
Last-Mile Delivery
E-commerce and courier companies integrate What3Words to route drivers to the exact entrance gate, loading bay, or back door — not just the building postcode.
Disaster Response & Humanitarian Aid
Plus Codes are used offline in field operations where internet is unavailable. Aid workers can pre-load OLC maps and locate distribution points using purely offline algorithms.
Navigation & Hiking
Hikers share meeting points in remote areas using Plus Codes. Google Maps displays them on long-press, making them easy to share between devices without mobile data.
How Plus Code Encoding Works
The Open Location Code algorithm converts decimal coordinates into an alphanumeric code using a 20-character alphabet (23456789CFGHJMPQRVWX). Vowels and easily confused characters are omitted to prevent offensive words and OCR errors.
A full 10-digit code encodes 4 "pairs" of digits (each pair covers one latitude and one longitude digit), followed by 2 "grid" digits that subdivide the remaining ~0.0025° × 0.0025° cell into a 5 × 4 = 20-cell grid. The '+' separator is inserted after the 8th character to make the code easier to read.
Encoding algorithm sketch
lat_norm = lat + 90 // range [0, 180] lng_norm = lng + 180 // range [0, 360] for each pair (resolutions 20, 1, 0.05, 0.0025): lat_digit = ⌊lat_norm / res⌋ mod 20 lng_digit = ⌊lng_norm / res⌋ mod 20 insert '+' after char 8 grid: subdivide 0.0025° cell into 5×4 = 20 sub-cells final lat cell ≈ 0.0001° (~11 m) final lng cell ≈ 0.00016° (~14 m at equator)
How to Convert Coordinates to What3Words
What3Words does not publish its word mapping algorithm publicly — conversion always requires an API call to their servers. Their free developer tier allows 1,000 conversions per day, which is sufficient for most personal projects and small apps.
To use What3Words in a Go application, make a GET request to api.what3words.com/v3/convert-to-3wa?coordinates=LAT,LNG&key=YOUR_KEY. The response JSON includes the three-word address, the square boundary, and the language.
Unlike Plus Codes, What3Words addresses are not bidirectionally derivable from the coordinate — you cannot reverse-engineer the words from a lat/lng without the API, nor decode a three-word address without an internet connection.
Location Precision Comparison
Bar widths are log-scaled. GPS precision depends on hardware and HDOP — consumer receivers typically achieve 3–5 m accuracy regardless of decimal places stored.
Frequently Asked Questions
How do I find a What3Words address for any location?
Open this tool, enter the latitude and longitude in the form above, and click Convert. If the server has a W3W_API_KEY configured, the three-word address appears instantly. Alternatively, open Google Maps, long-press any location, and tap the coordinates — the What3Words app can then read the clipboard coordinate.
Can I use Plus Codes without a Google account?
Yes. Plus Codes are open source (Apache 2.0) and completely free to use without any account, key, or internet connection. This tool encodes and decodes Plus Codes using a pure Go implementation of the Open Location Code algorithm.
What does a full 10-digit Plus Code look like?
A full Plus Code has exactly 10 alphanumeric characters plus the '+' separator at position 9, for example '87G8Q2PF+GF'. The first 8 characters encode the lat/lng in pairs at decreasing resolutions. The 2 characters after '+' encode a 5×4 sub-cell grid for ~14 m precision.
How accurate is What3Words for emergency services?
Each What3Words square is 3 × 3 metres, which is accurate enough to identify the exact entrance to a building or a specific field. In practice, the limiting factor is the GPS accuracy of the caller's handset (typically 3–10 m for consumer devices), not the What3Words encoding precision itself.
Does What3Words work in every country?
Yes. What3Words covers the entire land surface of Earth, including Antarctica, and has expanded to oceans for maritime use. The same three words always refer to the same location regardless of the user's country or language setting, though local-language word sets exist for over 50 languages.
How do I share a Plus Code with someone?
Copy the full Plus Code from this tool (e.g. 87G8Q2PF+GF) and share it via any messaging app. The recipient can paste it into Google Maps search — the app recognises the format and navigates to the location. For offline use, any OLC-compatible app or library can decode the code without internet access.
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